Stacks drift. You buy a tube here, a few coins there, a bag of old 90% at an estate sale — and eighteen months later “roughly fifty ounces-ish” is the honest answer to what you own, and nobody, including you, knows what it cost. The fix isn't discipline so much as one accounting decision made early: track everything in fine weight. The rest of this article is what that means and the four numbers it produces. It's also the logic inside our bullion portfolio calculator, which does the arithmetic for a stack of any shape.
1. Fine weight vs gross weight
Gross weight is what a coin weighs on the scale. Fine weight is the pure precious metal inside it. Almost no bullion product is pure-throughout, so the two differ more often than not, and only one of them can be added across products. The canonical example: a 1-ounce Gold Krugerrand is 22-karat alloy weighing about 1.0909 troy ounces on the scale — but contains exactly 1.000 troy ounces of gold. Add a Krugerrand to a .9999 Maple Leaf and you hold 2.000 fine ounces; add the gross weights and you get a number that means nothing.
The same normalization applies to odd holdings. A $1-face lot of worn 90% US silver counts as 0.715fine ounces. Sterling tea sets count at 0.925 of their weight. Once every line of your ledger is fine weight, “how much gold and how much silver do I actually own” becomes a sum instead of an estimate.
2. Troy ounces, regular ounces, pennyweights
A troy ounce is 31.1035 grams — about 10% heavier than the 28.35-gram avoirdupois ounce your kitchen scale and your postal rates use. All spot prices and almost all bullion products are quoted per troy ounce. Mixing the two ounces understates a stack by roughly ten percent, which is the kind of error that's embarrassing in a spreadsheet and expensive at a dealer.
The third unit you'll meet is the pennyweight (dwt),1.55517grams — the traditional jewelers' and pawnshops' unit, 20 to the troy ounce. Nothing wrong with it, but quotes in pennyweights look bigger per unit than they are; convert everything to troy ounces before comparing offers. (Our premium calculator accepts all three units for exactly this reason.)
3. What to write down per purchase
Five columns, one row per product per purchase date:
- Product — “Silver Eagle”, “90% halves, $50 face”, “1 oz gold bar (brand)”
- Fine content per unit — 1.000 ozt; 0.715 ozt; 1.000 ozt
- Quantity — coins, bars, or face dollars
- All-in cost — price including tax, shipping and surcharges; per unit and total
- Date and dealer — the column you'll thank yourself for when something needs reselling or verifying
That's the entire discipline. No weights of packaging, no gross weights, no “approx” — fine content times quantity, and the true out-of-pocket number.
4. The four numbers that describe a stack
With the ledger in fine weight, four sums fall out:
- Cost basis — total dollars paid. Your actual position in the trade.
- Melt value — total fine ounces × today's spot, per metal. What the metal is worth right now.
- Unrealized P/L — melt minus cost, in dollars and percent. The honest scorecard.
- Average premium paid — (cost − melt) ÷ melt, across everything. How much of your money bought product instead of metal.
Gold and silver sum separately — allocation by metal needs the two buckets — and the whole stack gets one more reality check: a liquidation estimateat a realistic dealer bid, because that's the number you'd actually receive on a Monday morning, not the melt number.
5. Premium drag: why flat spot shows a loss
The first time a stack tracker sees spot unchanged and a negative P/L, the usual conclusion is a spreadsheet bug. It isn't — it's the premium doing what premiums do. If your average premium paid is 8%, then at unchanged spot your stack is worth 8% less than you paid by construction, and a dealer's sub-spot bid makes it worse still. Spot has to rise by roughly your average premium — more, after the bid — before the position turns green at resale.
This is also why the average-premium number is worth watching on new purchases rather than admiring afterwards: it is the price of admission you chose. Our premium calculator prices each candidate purchase before it joins the ledger.
6. The yearly 15-minute review
Once a year, or after any meaningful purchase or sale: update spot to today's price, recompute the four numbers, and write down the date. That's it. The point isn't day-trading your own drawer — it's that a dated record turns “I'm up a bit, I think” into an actual answer, spots a missing tube quickly, and gives your heirs something better than a mystery should it ever matter. Insurance schedules and estate paperwork both get dramatically easier from the same five columns.
7. Run the whole stack in one place
The bullion portfolio calculator is this article as a tool: presets for common coins and junk-silver face lots, custom fine-weight rows for everything else, and the four numbers plus allocation and a bid-based liquidation estimate computed live. If you're still sorting a jar of inherited coinage into that ledger, start with the identification checklist and the junk silver calculator.
Bookkeeping, not advice: nothing here recommends buying or selling precious metals — for that, talk to a qualified financial professional.